Moths with a taste for tears: Insects that live off the tears of mammals find the secretions a tasty and nutritious food. The moths wisely favour mild-mannered herbivores as their victims

By HANS BANZIGER

Insects are renowned for their strange tastes in food, but few rival
Lobocraspis griseifusa, a moth from Southeast Asia. To find it, you must
go to the forest, wait until nightfall, then look into the eyes of an amenable
water buffalo. If your luck holds, you will witness a jostling crowd of
moths intent on a single delicacy: tears.

When researchers first announced that certain moths drank tears, their
reports were greeted with scepticism. Some entomologists thought it a freak
behaviour, or suspected that the insects involved were flies rather than
moths. Yet subsequent research has revealed tear drinking to be a specialised
and sophisticated strategy, with important medical and veterinary implications
.

Moths that drink tears are fastidious in their tastes, restricting their
attentions to certain species of animal. The usual victims are either hoofed
mammals, such as cattle and other bovids, deer, horses, tapirs and pigs,
or elephants – and, on occasion, people. Researchers have yet to witness
moths visiting the eyes of carnivores, marsupials, birds, or members of
any other group of vertebrates. This preference for certain hosts is not
yet fully understood, but it may reflect differences in the chemical composition
of tears from different animals. Another factor could be the host’s behaviour.
The most frequent victims are the most placid and tolerant mammals – an
important consideration for insects that habitually fumble around the eyes
of large animals with intent to steal.

Moths adopt a variety of ingenious techniques in their quest for tears.
Lobocraspis griseifusa, which is one of the most highly evolved tear suckers,
irritates the eye of its victim, thereby inducing …

To continue reading this premium article, subscribe for unlimited access.